Asthma preventer has a very good effect when used for long term.
Your father will be: 1) symtom free, 2) there will be minimal or no asthma attacks, 3) quality of life is improved, 4) there will be reduced chances of getting hospitalised for asthma attack, 5) there will not be any permanent changes in the lungs which occurs if asthma is not treated properly.

To avoid asthma you need to avoid strong smells, dust, smoke, cold foodstuffs and sour food items.
You also need to take inhalers regularly if prescribed by your doctor.
If you are allergic to things which you are unable to pin point then go ahead with skin allergy test.

Are you allergic to dust/cold foodstuffs?
do you feel whistling sound while breathing?
you should avoid any further cigarette smoking.
Drink a lot of water.
Have syp. Ambroxol xp 10 ml twice a day for 7 days.

Swimming is the best form of activity and exercise for asthmatics.
You can try ayurvedic medicines but beware that many such medicines have steroids in it. And also ayurvedic medicine will also be required for long term. It will not cure the asthma.. They too have side effects and at times can be severe too.

1st of all, he still needs to continue his tb medicines and complete the entire course as per his treating doctor.
Yes he has increased chances of getting a tb disease in future if his immune system becomes weak due to any reasons like diabetes, kidney disease, any drugs affecting immunity or poor diet causing weight loss.
He should keep a regular, healthy diet in future and avoid fasting or skipping meals.
He should reveal this history of tb whenever he visits a doctor for any illness or surgery.

You might be suffering for infection in your lungs or in the covering around the lungs.
Get a complete blood count (cbc) and xray chest (pa) done.
Visit your family physician with these reports and he can do the further treatment required.
Coughing for more than 2 weeks can be a sign of tuberculosis.

If you are stable with the medicines continue with the same and consult your physician to decide whether it can be tapered.
If you are still symptomatic i. E. Suffer from cough or breathlessness then you need to increase the dosage of your rotacaps.
Keep a regular follow up with a chest physician near you.

Symptoms of tb in general are low grade fever, weakness, loss of appetite, weight loss, feeling tired.
Other symptoms are dependent on the organ affected by tb.
Most commonly it is lungs, so the symptoms are usually cough, sputum production, breathlessness etc.
It spreads through close contacts basically if the patient with lung tb coughs out or slits in open or sneezes without covering his mouth.

If you have been diagnosed as asthma then you need to be taking inhalers for the same on a regular basis for time being.
Avoid cold foodstuffs, coloured food items and strong smells.
Get a spirometry done and cbc with xray chest (pa).

Best medication for asthma is to use inhalers.
Inhalers are absorbed in negligible amounts in the body hence they hardly have any side effects.
The usual side effects seen is sore throat and occasionally tremors.

You have not mentioned if you get breathless at times or feel chest tightness.
If you are diagnosed to be suffering from asthma then you should be taking inhalers and have regular follow up with your doctor.
Avoid cold foodstuffs, strong smells, dusts etc.